8ANALOG

W DEVICESUltraHigh-Speed

12-BitAIDConverter

FEATURES12-Bit Resolution500kHz Word RatesInternal Track-and-HoldSingle 4O-Pin DIP

APPLICATIONSMedical InstrumentationRadar SystemsTest SystemsWaveform AnalysisFast Fourier Transforms

8

GENERAL DESCRIPTION

The HAS-1204 AID Converter is a complete 12-bit hybrid AIDconverter in a single 4O-pin metal DIP. In this context, "complete"means the unit includes a track-and-hold (T/H) amplifier, encoder,and all the necessary timing circuits. It is a remarkable, self-con-tained device ready to perform the conversion function withoutthe need for external circuits.

The maximum conversion time of the HAS-1204 is 2.0 micro-seConds, including the acquisition time of the internal T/H. Thelarge-signal bandwidth of the T/H is 4MHz and the small-signal

ENCODE COMMAND ( 1

8

bandwidth is 7MHz. This combination of characteristics assuresthat the HAS-1204 will operate at word rates from dc through500kHz, digitizing analog signals containing frequency compo-nents to 250kHz with minimum attenuation or distortion.

Integrating the T/H, encoder, and timing circuits into a singlepackage allows optimum matching of T/H-encoder parametersto obtain the best possible performance. It also lowers the overallpower dissipation to a maximum 2.2 watts, making the HAS-1204an ideal choice for designers who face space and/or power re- -strictions for their designs.

HAS-1204

SUCCESSIVE-APPROXIMATION

REGISTER

2) DATA READY

D/ACONVERTER

HAS-1204 Block Diagram

Information furnished by Analog Devices is believed to be accurateand reliable. However, no responsibility is assumed by Analog Devicesfor its use; nor for any infringements of patents or other rights of thirdparties which may result from its use. No license is granted by implica-~ion or otherwise under any patent or patent rights of Analog Devices.

Route 1 Industrial Park; P.O. Box 280; NolWood, Mass. 02062Tel: 617/329-4700 TWX: 710/394-6577

West Coast Mid-West Texas7141641-9391 312/653-5000 214/231-5094

OBSOLETE

SPEeIFieATIONS (typical @ + 25"C with nominal power suppliesunlessoU1erwisenoted)

OUTLINE DIMENSIONSHAS-1204SM

**

*****

**********

**

*

- 55 10 + 100*

*

435338

-2-

Dimensions shown in inches and (mm).

0.19 14.831

MA~

O'4~Jrrmm-mmmrrMIN-r-.

0.1"131751'°.010

I r O.'OOI'54}~ '°.00' 10 BEAD ION BOTTOM} AND

A 19 PLACES "---yO' IONTOP}DENOTEPIN'

I TFrFO_O+H_O_O-O-o_o_o_o_o-o-F~ ~~ "~ :8~ g~ 0~ 0

~ lLJ-Lo-o-o_o-o-o-o -o-o-o-o-o-o-o-o-o-o-L4°, I :21

I '.900148.'OO},..." .1'.145 }54..'} MAX

HAS-1204 PIN DESIGNA nONS(As viewed from bottom)

NOTES'Specification same as HAS-1204BM'In-band bsrmonics expressed in terms of spurious in.band signaJsgeoerated at 500kHz encode rste at analog input frequenciessbown in ( ).

'RMS signal to rms noise rstio witb 50kHz analog input and encode rate of500kHz; input signal at -1.0dB.

'For full-scale step input, 12-bit acCUrBCyattained in specified time.4Recoversto specified performance in specified time after 2 x FSinput voltage.

'Witb analog input 4OdBbelow FS.'witb FS analog input. (Large-signa] bandwidtb flat within 0.5dB,dc to IMHz).

'Eacb input frequency applied at a level 7dB below full scale.'Extemally adjustable to zero.'Transition from digital "0" to digital "I" initiates eocoding.'OUsetrailing edge of ~ pulse to strobe digital outpurs into

external circuits (See Figure 2)."Power dissipation shown is at zero input. Power dissipation is 2.3 Watts

maximum for - IOV input.12T ~ Case tempersture.

"Maximum junction temperature ~ 150°C. Opersting unit requires500 cubic feet per minute (CFPM) moving air.

Specifications subject to cbange witbout notice.

HAS-1204BM

RESOLUTION (FS =Full Scale) Bits (%FS) 12(0.024)LSBWEIGHT

5VInputRange mV 1.2210VInput Range mV 2.44

ACCURACYLinearity @ de %FS ::!:1I2LSB 0.0125Monotonicity GuaranteedNonlinearityvs. Temperature ppml"C 3Gain Error %FS (max) 0.1(0.7)Gain yo.Temperature ppmI"C 35

DYNAMIC CHARACTERISTICSIn-Band Harmonics!

(de to 60kHz) dB belowFS 75(60kHz to 120kHz) dB below FS 75(120kHz to 200kHz) dB below FS 70

Conversion Rate kHz 500Conversion Time ILs,max 2.0Aperture Uncertainty Gitter) ps 60Aperture Time (Delay) ns(min/max) 10(4/18)Signal to Noise Ratio (SNR)2 dB 69Transient Response3 ns 400Overvoltage Recovery' ns 900Input Bandwidth

Small Signal, - 3dB' MHz 7Large Signal, - 3dB6 MHz 4

Two-Tone Linearity(@ Input Frequencies)'(37.5kHz;52.5kHz) dB below FS 85

ANALOG INPUTVoltage Ranges V,FS Oto-5;Oto-1O *

::!:5;::!:2.5Overvoltage V,max 2xFS *

Impedance5VRanges .0 (max) I ,000 (::!: 10) *IOVRanges .0 (max) 2,000(::!:20) *

Offset"

Initial-IOV Input mV(max) 10(60) *

vs. Temperature (Unipolar) FS ppml"C IS *

yo.Temperature (Bipolar) FS ppml"C 50 *

ENCODE COMMAND INPUT'

Logic Levels, TTL-Compatible V "0"=010 +0.4 *

"1"= + 2.4 to +5 *

Impedance LS TTL Loads 2 *Rise and Fall Times ns, max 10 *Width

Min ns 90 *Max ns 160 *

Frequency kHz dc to 500 *

DIGITAL OUTPUTIOFormat Data Bits 12Parallel;NRZ *

Data Ready I;RZ *

Logic Levels, TTL-Compatible V "O"=Oto +0.4 *

"1"=+2.4to+5 *Drive TTL Loads I StandardCoding

Unipolar Mode ComplementaryBinary (CBN)

Bipolar Mode Complementary *

Offset Binary(COB)

POWER REQUIREMENTS+ 15V ::!:O.5V mA,max 54 *-15V::!:O.5V mA, max 40 *+ 5V ::!:O.5V mA, max 160Power Dissipation II W,max 2.2

TEMPERATURERANGEI2Operating °C - 25 to + 85Storage °C -65to+150

THERMALRESISTANCE13

JunctiontoAir,9ja(Free Air) °CIW 25

Junction to Case, 9jc °CIW 16PRICES

(1-24) $ 378(loo's) $ 294

For applications assistance, call CompUter Labs Division @ (919)668-9511

PIN FUNCTION PIN FUNCTION

40 ANALOG GROUND 1 ENCODECOMMAND39 1OVRANGE 2 DATAREADY38 5VRANGE 3 ANALOG GROUND37 GAIN ADJUST 4 +5V36 -15V 5 -15V35 +15V 6 DIGITALGROUND34 +5V 7 BIT 1 (MSB)33 DIGITALGROUND 8 BIT232 FACTORYUSE ONLY 9 BIT331 FACTORYUSE ONLY 10 BIT430 -15V 11 BIT529 BIPOLAROFFSET 12 BIT628 D/AOUTPUT 13 +5V27 ANALOG GROUND 14 DIGITALGROUND26 ANALOG GROUND 15 BIT725 ANALOG GROUND 16 BIT824 ANALOG GROUND 17 BIT923 ANALOG GROUND 18 BIT1022 CLOCKOUT 19 BIT1121 SERIALOUT 20 BIT12(LSBI

OBSOLETE

THEORY OF OPERATION/TIMINGRefer to the block diagram of the HAS-1204.

Analog input signals to be digitized are applied to either Pin 38(5V RANGE) or Pin 39 (IOV RANGE), depending upon theiramplitude. These signals are inputs to the internal track-and-hold(T/H) which is nonnally operating in the "track" mode as abuffer amplifier, following all changes in analog as they occur.

An external strap, shown between Pin 28 and Pin 29, is used ifoperating the converter in the bipolar mode; it is important tokeep this strap as short as possible. For unipolar operation,connect Pin 29 to ground.

The user determines the point at which the digitizing process isto be initiated by controlling the application of the TTL-compatibleEncode Command pulse. Its positive-going leading edge switchesthe T/H to the "hold" mode of operation, "freezing" the analoginput signal and beginning the digitizing process. As shown inthe block diagram, the Encode Command applied to Pin 1generatesthe required timing signals within the HAS-1204 AID, makingit unnecessary to add external circuits.

The held value of analog input is part of the input to a high-speedcomparator within the converter. The other input is the analogoutput of the internal high-speed, high-accuracy D/A converter.The resulting output of the comparator is applied to the successiveapproximation register (SAR), also controlled by timing signalsinitiated by the encode command.

Digital outputs are available in both serial and parallel formats,as shown in Figure 1, HAS-1204 Timing.

Times shown in the timing diagram are typical times, unlessnoted otherwise. In the illustration, the Track/Hold signal isinternal, not available to the user; it is included to help understandthe operation of the converter.

I-

ENCODEJ MIN=90ns ICOMMAND" ..

~ ~::s160nsTRACK/HOLD'r(lNTERNAL!..-J

1.55f'S

I-CLOCK

SET-UPPULSE

f- ~230ns

DATA .-J FREADY~ 80ns

--j t--- 20ns

IBIT1

Timing intervals are measured from the leading edge of theEncode Command supplied by the user; this makes it easier toestablish appropriate system timing.

Note the trailing edge of each clock pulse occurs after its corres-ponding serial output infonnation has changed. If the serialoutput of the HAS-1204 converter is the desired signal, thetrailing edges of clock pulses should be used as the stobes.

To assure the serial output data are fully established, the user isurged to incorporate a delay of approximately 30 nanosecondsbetween the trailing clock edge and the latch. This compensatesfor latch setup time, and slight variations in timing between theclock pulses and their associated data.

The portion of Figure I pertaining to Data Ready timing showsit returns to the digital "0" state 10 nanoseconds before thetrack-and-hold switches from "hold" to "track". The trailingedge of clock pulse # 12 and the "track" transition are time-coinci-dent, so this change in Data Ready occurs 10 nanoseconds beforethe trailing edge of the last clock pulse; and at the same time asthe Bit 12 data change.

Time coincidence between the change of the Data Ready pulseand the arrival of Bit 12 (LSB) data might seem to precludeusing the Data Ready pulse as a strobe. Despite that initialimpression, the trailing (falling) edge of the Data Ready is rec-ommended for strobing the parallel outputs into external circuits.This can be accomplished by using an inverter with a time delay(to) of the appropriate amount for the latch which is beingused, as illustrated in Figure 2.

The timing relationships discussed above are generated internallybecause the clock pulses' rising edges control the switching. The30-nanosecond width of each clock signal helps assure that itsserial output data are firmly..established by the time the clock'strailing edge arrives.

2.0f'S -j

j1

I_TRACK_ILI~ =~50~S"':J

---Yl R--1 ~ 10ns

I

- --

- --- --

---I

c===~BIT12

.# SERIALOUTPUT

I

I -1211

Figure 7. HAS- 7204 Timing

-3-

-

OBSOLETE

DELAY (to)= 15n5 + LATCH SETUPTIME

HAS-1204

Figure 2. Output Strobe

APPLICATIONS INFORMATION

Figures 3 and 4 provide needed details on the adjustment ofcontrols for setting the amount of offset and gain.

As noted in both illustrations, the OFFSET control must be setfirst for proper performance of the converter. Since the HAS-1204is capable of operating in either a unipolar or bipolar mode,OFFSET ADJUST and GAIN ADJUST include informationfor both.

~l-15V Hl-15V

10k10k

NOTESA. ADJUST OFFSET CONTROL BEFORE GAIN

CONTROL.B. FOR UNIPOLAR OPERATION. CONNECT

PIN 29 TO GROUND.C. FOR BIPOLAR OPERATION. CONNECT PINS 28

AND 29 WITH SHORT JUMPER.

UNIPOLAR ~ 5V RANGEAPPLY -1/2LSBTOINPUT: -1.2mV -0.6mV

(@PIN39) I@PIN38)ADJUST FOR BIT 12 "DITHER" IN DIGITAL OUTPUT WORD: 000 000 000 OOX

BIPOLAR ~ 5V RANGE

APPLY RANGE -1I2LSBTOINPUT: +4.9988V +2.4994V2 (@PIN391 I@PIN38)

ADJUST FOR BI112 "DITHER" IN DIGITAL OUTPUT WORD: 000 000 000 OOX

Figure 3. Offset Adjust

~10V RANGE 5V RANGE

HAS-1204 HAS-1204

NOTESA. ADJUST OFFSET CONTROL BEFORE GAIN

CONTROL.B. FOR UNIPOLAR OPERATION. CONNECT

PIN 29 TO GROUND.C. FOR BIPOLAR OPERATION. CONNECT PINS 28

AND 29 WITH SHORT JUMPER.

~APPLY + 1-1/2LSBTO INPUT:

10VRANGE 5VRANGE

-9.9963V -4.9982VI@PIN39) I@PIN381

ADJUSTFORBIT12 "DITHER" IN DIGITAL OUTPUT WORD: 111 111 111 IIX

BIPOLAR 10VRANGE 5VRANGE

APPLY -RANGE + 1.1/2LSBTOINPUT: -4.9963V -2.4982V2 I@PIN391 I@PIN381

ADJUSTFORBITI2"DITHER"INDIGITALOUTPUTWORD:111 111 111 11X

Figure 4. Gain Adust

However, careful adjustment of available controls is not the onlyway to help assure optimum performance. Like all high-speed,high-resolution components, the HAS-1204 is also sensitive tolayout constraints. The use of a large, low-impedance groundplane is imperative.

In addition, bypass capacitors on the power supply leads arerecommended. For most applications, electrolytic capacitors of10-22 microfarads in parallel with ceramic capacitors of O.OIJLFto O.IJLFwill enhance the converter's effectiveness. These shouldbe connected as closely as possible to the power supply pinsentering the hybrid.

To prevent cross-coupling of analog and digital signals whichmay "mask" lower-order bits, analog and digital signal pathsshould be physically separated as much as possible. The user isurged to pay careful attention to both electrical and mechanicaldesign to obtain best results.

ORDERING INFORMATIONTwo versions of HAS-1204 AID Converters are available asstandard products; both are housed in 4O-pin hermetically-sealedmetal packages. With the exception of operating temperatures,the specifications are the same for both units. For a temperaturerange of - 25°C to + 85°C, specify the model HAS-1204BM; fora range of - 55°C to + 100°C, order model number HAS-1204SM.Units screened to military requirements are also available; contactthe factory for details.

-4-

8

on~to-~J,NenU

8

<i.- en

::j~cw~zit:c..

8

OBSOLETE